ARTICLE TOOLS

The cover picture shows a SEM image of polypyrrole (PPY) as presented on page 1327 by Ai-Qin Zhang, Yuan-Hua Xiao, Ling-Zhen Lu, Li-Zhen Wang, and Feng Li. The synthesis of PPY is carried out at a constant temperature of 0°C. First, FeCl3 (oxidant) is dissolved in 1 mol/L HCl. Second, after 1 hour of stirring, pyrrole is added into the solution. Finally, the precipitates are separated by filtration, rinsed with 0.01 mol/L HCl, water, and acetone three times each, and dried at 60°C in a vacuum oven. The specific capacitance of the PPY electrode is 246.2 F/g at a current of 8 mA/cm2 when used as the electrode material of a supercapacitor.